Maximising the benefits of rainwater harvesting technology towards sustainability in urban areas of South Africa: a case study

ABSTRACT

Rainwater harvesting (RWH) technology has been in use for a long time, however its contribution towards urban water supply has been negligible in South Africa. Through a comprehensive literature review and analysis of interviews with key stakeholders, this case study presents implementation challenges and policy gaps in relation to the scale of adoption in the City of Johannesburg (CoJ). Findings show that only 0.1% of CoJ’s population utilises RWH due to various reasons, varying from financial viability, reliability, quality concerns, and system maintenance. This paper attributes these to the scale of adoption and suggests upscaling the system to larger commercial buildings to optimise benefits. However, there is an urgent need to bridge the policy gaps for successful implementation. Three categories of policy reforms are therefore proposed to facilitate innovation uptake, stakeholder engagement and compliance. This knowledge can guide future research towards urban water management, scientists and policymakers nexus.     

某超高层建筑给水和热水系统设计

超高层建筑给水和热水系统应安全可靠、经济合理、高效节能。论文结合某工程实例,对给水和热水系统的设计进行了分析讨论,并介绍了采用的节水和节能措施。     

X市供水系统规划及问题探讨

对X市供水现状及存在的问题进行分析,介绍了X市供水系统规划的主要内容,并对规划中存在的水资源分析、供水设施设置、水源置换、节水潜能分析、污水回用、水价等问题进行了探讨。     

A sustainable framework for water resources management in an urban watershed: the case of Volos,Greece

The implementation of sustainable development principles in water resources management refers to an integrated management and coordination of the entirety of the actions and interventions that concern the water ecosystem, or parts of it, within a watershed. This procedure is accomplished through the development and application of an overall management plan at a hydrological basin level. This concept was followed by the water resources management plan of the city of Volos' watershed, which is presented in this paper. The main objective is the choice of the best set, among others, of hydraulic projects, which will be able to re-establish the balance in the basin's deficient water budget, satisfying at the same time future urban water demand. Decision making was carried out using a GIS tool and involved traditional water capture hydraulic projects on the one hand and sustainable water saving measures on the other. The whole procedure is being developed in an area with serious environmental problems, concerning mainly the groundwater resources. The particularity here is that the alternative solutions strongly depend on administrative agreement and consensus between relevant authorities.     

A review of residential water conservation tool performance and influences on implementation effectiveness

Water scarcity and household water consumption has received increasing attention on national public agendas in recent years. At the same time a number of important demand-side management (DSM) studies have been reported on by non-academic institutions, and there is a need for a comprehensive, up to date review of the impacts of DSM tools and the factors which influence their effectiveness. This paper aims to address an apparent lack of coverage in the academic literature by presenting a review of residential DSM tools using reports of recent DSM campaigns in the western (developed) world. The central objectives are to understand the potential for residential DSM tools to save water in different types of household under varying conditions and to identify influences on implementation effectiveness. In the discussion, we explore causes of uncertainty in DSM planning including the non-transferability of trends and existing methods of evaluation, and describe some of the resulting problems. The conclusions offer recommendations as to areas that require, and offer the greatest scope, for future research. This review article will be of interest to, among others, water company professionals, policy makers, regulators, researchers, and environmental agencies.     

Water safety plans for piped urban supplies in developing countries: a case study from Kampala,Uganda

Full cost recovery is a major and complex issue that has gained high recognition in recent years. The Water Framework Directive promotes the idea that water charging should act as an incentive for the sustainable use of water resources. Thus, all Member States should take into consideration the principle of recovery of the total cost of water services, which includes environmental and resource costs as well. In order to evaluate various aspects of current water policy, to investigate the perspectives of water saving, to explore new approaches toward sustainable water management in the water supply sector and to evaluate water price elasticity, a survey has been performed recently in the city of Volos, concerning the residential sector. The influence of some selected variables is examined, residential water demand curve and water price elasticity are calculated. Estimations of future water demand under different pricing policies are also performed. Finally, the full water cost for the city of Volos is estimated and essential conclusions concerning water pricing and public participation are drawn.     

Water Supply and Demand Balances: Converting Uncertainty Into Headroom

This paper reports on research into the development of a standard procedure for calculating headroom. Headroom is a legitimate planning allowance to account for uncertainties in the supply/demand balance in a water-resource plan. Prior to this research, the UK water industry did not have an agreed method for calculating headroom, which resulted in inconsistencies in regulatory submissions. The research built on previous studies to define an approach that would be practical and easy to apply. A pragmatic methodology using a series of forms with clear guidelines was developed. The methodology has been applied in the 1998 supply/demand balance submissions to the regulatory authorities as part of the Asset Management Plan 3 periodic review.     

Public engagement with water conservation in London

Understanding water demand and consumers' capacity for change is essential in underpinning water demand management and water efficiency programmes. This paper presents the outcomes of a qualitative study, which used discussion groups relating to water infrastructure with environmentally aware citizens in five London boroughs in the Lower Lea River Basin. The results showed a subtle interaction between users, water and technology. Users are generally unaware of their own water consumption. Individual perceptions of changes in water behaviour are constrained by habit and lack of knowledge about what changes can be made and how. Knowledge of environmental information was described as the inspiration behind making any changes. The paper concludes that access to information about water resources, infrastructure and conservation measures should be enhanced because although information sources are abundant, participants claimed they were inaccessible without considerable effort. Finally, an emphasis should also be put on helping the public form a more substantial part in environmental decisions.     

Estimating Small Area Demand for Water: A New Methodology

The estimation of water demand is fundamental to effective water resource management. Water supply is measured at district level but true demand is not, and therefore studies of water-pricing relations are limited and mass-balance based assessment of leakage, illegal use, meter inaccuracies etc., are compromised. This paper describes the value and limitations of existing geodemographic methods, and an alternative technique widely used in other fields, microsimulation, is proposed. It is shown that geographic stability in demand relations is not found in all consumer commodities and cannot be assumed for water. Sampled data for Leeds, West Yorkshire, are used to construct a microsimulation model, and the results of that model are applied to the city of Leeds at ward level. Applicability is also demonstrated at enumeration district level.     

Water demand management: implementation principles and indicative case studies

Current practices for the efficient use and management of water resources are based on the conjunctive application of water supply and demand measures. Even though options for the augmentation of water supply are widely analysed and assessed, water demand management remains an open field for study, as it is highly dependent on the socio‐economic features of a region and has a site‐specific character. This paper summarizes the guiding principles of demand management and presents some successful application examples of demand management measures from regions that cover a wide range of socioeconomic and environmental conditions in an effort to identify the critical factors for the efficient planning and implementation of demand management plans.     

高校校区给排水设计中的节能措施

针对高校校区工程特点,分别分析了生活给水系统、热水系统及排水系统中的节能措施在高校给排水设计中的可行性,并提出高校通过节水达到节能的几点措施,以达到最佳综合节能效果。     

高等学校照明节能改造——以四川某大学校区为例

我国校园照明用电节能潜力巨大.在大量浏览照明节能改造相关文献的基础上,通过市场调查和对成都3所高校的实地调研,以四川某大学主要教学楼为研究对象,对其进行高效照明节能改造方案设计,并对改造方案进行节能与经济分析,主要探究以LED照明替代教室现有照明的节能潜力与经济性,研究表明可将针对研究对象量化的节能潜力推广至全国高校.     

Chemical drinking water quality in Ghana: Water costs and scope for advanced treatment

To reduce child mortality and improve health in Ghana boreholes and wells are being installed across the country by the private sector, NGO's and the Ghanaian government. Water quality is not generally monitored once a water source has been improved. Water supplies were sampled across Ghana from mostly boreholes, wells and rivers as well as some piped water from the different regions and analysed for the chemical quality. Chemical water quality was found to exceed the WHO guidelines in 38% of samples, while pH varied from 3.7 to 8.9. Excess levels of nitrate (NO₃⁻) were found in 21% of the samples, manganese (Mn) and fluoride (F⁻) in 11% and 6.7%, respectively. Heavy metals such as lead (Pb), arsenic (As) and uranium (U) were localised to mining areas. Elements without health based guideline values such as aluminium (Al, 95%) and chloride (Cl, 5.7%) were found above the provisional guideline value.Economic information was gathered to identify water costs and ability to pay. Capital costs of wells and boreholes are about £1200 and £3800 respectively. The majority of installation costs are generally paid by the government or NGO's, while the maintenance is expected to be covered by the community. At least 58% of the communities had a water payment system in place, either an annual fee/one-off fee or “pay-as-you-fetch”. The annual fee was between £0.3-21, while the boreholes had a water collection fee of £0.07-0.7/m³, many wells were free. Interestingly, the most expensive water (£2.9-3.5/m³) was brought by truck. Many groundwater sources were not used due to poor chemical water quality. Considering the cost of unsuccessful borehole development, the potential for integrating suitable water treatment into the capital and maintenance costs of water sources is discussed. Additionally, many sources were not in use due to lack of water capacity, equipment malfunction or lack of economic resources to repair and maintain equipment. Those issues need to be addressed in combination with water quality, coordinated water supply provision and possible treatment to ensure sustainability of improved water resources.     

Recognising barriers to implementation of Blue-Green Infrastructure: a Newcastle case study

There is a recognised need for a fundamental change in how the UK manages urban water and flood risk in response to increasingly frequent rainfall events coupled with planned urban expansion. Approaches centred on ‘living with and making space for water’ are increasingly adopted internationally. Nonetheless, widespread implementation of Blue-Green Infrastructure (BGI) is currently hampered by barriers that impede uptake and innovation. We investigate the barriers to implementation of BGI in Newcastle, UK, through a series of semi-structured interviews with professional stakeholders. We identify and categorise 17 types of barrier and identify targeted strategies to overcome the dominant barriers. We recommend promotion of BGI’s capacity to meet the objectives of multiple organisations and Local Authority departments, in addition to managing urban water. We conclude that strong business cases, supported by monetised evidence of benefits, and collaborative, inter-agency working could advance implementation of BGI within the current flood risk management legislation.     

小区建筑调速供水的节能再论

随着现代建筑对节约成本、节能降耗的不断追求,调速供水的方式在生活小区、公共建筑中得到广泛应用.通过详速水泵调速节能技术的原理和具体实现方式,就其应用的节能效果和应注意的问题作深入探讨.     

Water use,sanitation and health in a fragmented urban water system: case study and household survey

In a study to identify strategies to deal with rapid urbanization and threatening climate change, in Can Tho City, Vietnam, a survey of 1200 households was undertaken to investigate water access and sanitation services. The survey targeted three different groups based on their access to water services: (a) those with piped water supply, (b) without piped water, and (c) a mix of (a) and (b). Socio-economic factors and level of urbanization significantly influenced the different water sources accessed by households and their type of sanitation. Results indicated that householders often employed multiple water sources in an attempt to match source with intended use. The use of multiple water sources, levels of sanitation and the quality of water were found to be good indicators of reported rates of illness. Results also showed that the provision of piped water does not always provide the desired health outcomes, as the definition of adequate water supply does not include water quality objectives. Therefore, more detailed assessments may be required to understand how people use and access water and sanitation, and the impacts on public health.     

南方某市供水管网水质在线监测管理系统的建立

以南方某市为例，介绍了其供水管网水质在线监测管理系统的建立过程。首先，对系统进行总体设计，确定在线监测点的位置、数量和在线监测指标，选定在线监测仪器和在线数据传输方式。其次，基于管网水质在线监测信息建立了水质在线监测管理系统，可实现数据库连接、列表、查询、统计报表打印、实时监测数据显示等功能。最后，依据统计分析与人工智能的方法建立了三种水质预测模型，并将其与水质在线管理系统集成，实现了对供水管网主要水质指标的在线监测、管理与预测。对该系统采用管网实测数据进行考核、验证，结果令人满意。     

浅谈中国历史性大学校园发展过程及其特点

结合高等教育对我国社会发展的作用和近代历史性高等学校具有的双重价值,分析了中国历史性校园的发展过程和特点,指出中国历史性校园的发展并非一个健康自然可持续的有机过程,应对其未来的发展持谨慎乐观态度。     

Identifying regional landscapes for conservation planning: a case study from KwaZulu-Natal, South Africa

The application of landscape ecology in conservation biology has rarely occurred in the context of defined landscapes. Conservation planning has focussed on representation of species diversity patterns and assumed that ecosystems, landscapes and their associated processes will be equally protected. The long-term persistence of biodiversity in the face of land transformations and global change requires the representation and retention of all elements of biodiversity. This biodiversity includes landscapes, and the landscape structure and processes that maintain patterns of biodiversity. We developed a method of classifying landscapes for the KwaZulu-Natal province of South Africa. The process entailed the use of 1 km² grid data from climate and terrain databases. Principal components analysis coupled with a cluster classification method and spatial overlay techniques were used to identify two hierarchical levels of landscapes. Validation analysis showed that landscapes are identifiable with a classification accuracy of 86.8%. The derived landscapes can be combined separately with data on vegetation and soil to describe landscape ecosystems that potentially differ in species composition, successional dynamics, and potential productivity. The surrogate use of the landscapes in conjunction with other strategic data, for the identification of priority conservation areas, is demonstrated.